Shield for furnace tubes



Patented Mar. 5, 1935 'f 3. l l

UNIT-ED:

1,993,283 V SHIELD FOR FURNACE TUBES George Potts, Hillside, N. J.,assignorto Standard Oil Development Company, a, corporation of Delawareu Application May-5, 1931, Serial No. 535,195 Y 3 .Claim (Cl. 196-116)This invention relates Vto improvements i in by such beams is convenientbut it will be undermeans for protecting the tubes of a tube still,"Vstood that any other equivalent trough-like artubular reaction chamber,or the like,V from the rangement may be used forthe same purpose. Aadverse effect of excessive radiant heat. In a variety of heatinsulatingmaterials may be used.

5 preferred embodiment of the invention the 'tubes Fragments offire-brick, powdered clay or the 5 are protected by placing over them ashielding like are suitable? v structure, preferably oi thenature ofI-beams, While the protective means have been illusin such manner as tointercept the radiant heat. trated only in Vconnection 'with the top rowof A furtherV object of the invention is to secure tubes, it is obviousthat other Vtubes' could be 1 0 the stated Vprotection withoutsubstantially. imsimilarly protected if desirable.` Ordinarily the 10pairing the heat input from convection. toprow is the only one which islikely to receive The invention will beiully understood from excessiveheat radiation. With the construction the following description, Yreadyin connection with described it is possible to obtain all the desiredthe accompanying drawing, in which heating eiect by convection withoutoverheating Fig. 1 is a vertical sectionthrough a furnace the tubes byradiation. It will be observed that 15 in which the upper bank oftubesin the convecthe combustion gases passl freely around all the tionsection is protected by I-beams, tubes in the convection section. I amaware that Fig. 2 is a longitudinal Vsection `taken on the beams havebeen used adjacent tubes to transline 2 2 of Fig. l, and mitradiant heatthereto and obstruct convection Figs. 3 and 4 are enlarged perspectiveviews of heat. The present invention has an Opposite 20 Y tubes andalternative forms of protective means. UIICOD, aS described.

Referring rst to Figs. 1 and 2, reference nu- In Fig. 3 analternativeform of tube shield'is :neral 1 denotes a furnace setting which may beillustrated. This comprises a flat metallic bar of any suitable kind.Typical installations to 10 carrying on-its upper surface a thickVlagging which this invention are applicable include 11 of heatinsulating'material. The device shown 25 lcracking coils, hightemperature tube stills, tubuin Fig. 4 is a trough-like metallic member12 lar hydrogenation units and the like. In general which may be lledwith vclay 12' or the like. the invention is applicable whereverextremely Various means have been proposed heretofore high temperaturesare generated and applied to OI preVelltmg TadiatiOn fIQm the upper Wall01 liquids or gases flowing through tubes. In theV arch of the furnacebut such means have not 30 setting illustrated there is the usualbankvof tubes given uniformly Satisfactory SGIVCB in 0011116@- 2arranged in the radiant heat section 3 of the tion with very hightemperature ODBIBJODS, T01 furnace l. A bank of tubes a isinstalle'd ina example where the temperature of the convection chamber 5 whichreceives the hot combustion section'is 1800 F. or more. In suchsituations gases from chamber 3 through the flue 6. y the shieldingdevice of the present invention gives 35 n The upper wall 7 of chamber 5may be heated ample protection without decreasing the emciency toincandescence by the combustion gases. The of the furnace. heat fromthis Wallis radiated downwardly and Various changes and alternativearrangements would cause the tubes in the upper row of bank may be madewithin the scope of the appended 40 4- to reach too high a temperature.This is preclaims in which it is my intention to claim all 40 -vented byplacing over these upper tubes a series novelty inherent in theinvention as broadly as. of metallic protecting structures which aremost the prior art permits. conveniently in the form of I-beams 8. TheseI claim:k 1 1 I-beams are supported at several points inter- 1. Ahightemperature furnace comprising a mediate their ends by hangers 9,which pass radiant heat section and a convection heat seci5 through thetop of the chamber 5. The ends of tion, tubes in both said sections,means for prothe Lbeains are received in openings in the side tectingthe upper tubes in the convection section walls of chamber 5, and theseopenings are filled from radiant heat, said means comprising a withasbestos wall 5l or other similar material shielding element arrangedbetween each of the which will permit the -beam to expand and conuppertubes andthe adjacent radiant surface in 50 tract. y the convectionsection, and Vheat insulating ina- In order to increase the protectiveaction of the terial carried by each of said shielding elements.structure described it is preferred to place a heat 2.' The improvementin the process of destrucinsulating material 8 inthe upper portion oftive hydrogenation of carbonaceous materials,

A each I-beam. The channeled structure provided which comprises passinghot gases into a cham-Y 55 ber adjacent an arch in the chamber whichthrows out radiant heat, passing the carbonaceous materials in thepresence of hydrogen through spaced rows of tubes, and independentlyshielding each of the tubes adjoining the arch from the radiant heat ofthe arch While permittingl free passage of gases to the tubes.

3. In'combination with furnace tubes arranged adjacent to a source ofradiant heat, a protective structure adapted to decrease thetransmission of radiant heat to the tubes, said structure comprising aplurality of lshielding elements in the form of I-beams placed on theirsides so as to form an upper channel, heat insulating material in saidchannels, means for suspending the I-beams at points intermediate theirends so that they run parallel with and overlie the respective tubesbetween the same and the source of radiant heat, and means for mountingthe I-beams for expansible movement at their ends.

GEORGE POTTS.

